Limits...
Mirror focus in a patient with intractable occipital lobe epilepsy.

Kim J, Shin HK, Hwang KJ, Choi SJ, Joo EY, Hong SB, Hong SC, Seo DW - J Epilepsy Res (2014)

Bottom Line: Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then.The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area.This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Busan;

ABSTRACT
Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy. We have observed occipital lobe epilepsy with mirror focus. Before epilepsy surgery, the subject's seizure onset zone was observed in the left occipital area by ictal studies. Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then. The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area. This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.

No MeSH data available.


Related in: MedlinePlus

Electrophysiologic results in the first presurgical evaluation. (A) Interictal epielptiform discharges are observed in left occipital area (vertical scale: 50 uv, horizontal scale: 1 sec). (B) Ictal EEG shows evolving rhythmic discharges with sharp waves in the left occipital region, spreading to the right occipital area. This ictal EEG indicates left occipital ictal onset zone (vertical scale: 100 uv, horizontal scale: 1 sec). The patient’s seizure was left versive seizure during this ictal recording.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4066626&req=5

f1-er-4-1-34-9: Electrophysiologic results in the first presurgical evaluation. (A) Interictal epielptiform discharges are observed in left occipital area (vertical scale: 50 uv, horizontal scale: 1 sec). (B) Ictal EEG shows evolving rhythmic discharges with sharp waves in the left occipital region, spreading to the right occipital area. This ictal EEG indicates left occipital ictal onset zone (vertical scale: 100 uv, horizontal scale: 1 sec). The patient’s seizure was left versive seizure during this ictal recording.

Mentions: A 10-year-old girl had epileptic seizures for 4 years. She was right handed and her epileptic seizures consisted of a visual aura with flashes, unresponsiveness and oro-ailimentary automatisms like lip smacking. The visual aura occurred in the left, right, or whole visual fields. Sometimes her seizures evolved into secondarily generalized seizures. Her seizures were not completely controlled by a polytherapy with carbamazepine, lamotrigine, and valproic acid. In a neurological examination, no lateralizing or focal neurological deficits were noted. She had no family history of epileptic seizure. Initially she was admitted to a long-term video EEG monitoring unit (EMU) for presurgical evaluation. During 9 day stay, interictal epileptileptifom discharges were seen frequently in the left occipital area (Fig. IA). Ictal events were 31 simple partial seizures (SPS) and 11 complex partial seizures (CPS). Among the 31 SPS, 12 visual auras occurred on her right side, whose ictal EEG showed left occipital discharges in 9 SPS and the remaining 3 auras showed no EEG changes. The other 19 visual auras occurred on her left side, whose ictal EEG revealed left occipital discharges in 2 SPS and the remaining 17 auras showed no EEG changes. Among the 11 CPS, right versive seizures are in 7 seizures, dialeptic seizures in 3 seizures, and left versive seizure in 1 seizure. Secondarily generalization occurred in 5 seizures. All ictal EEG changes started in the left occipital area (Fig. IB). Her 3.0T high resolution brain MRI showed no definite abnormalities. She underwent ictal and interictal Tc-99m ECD SPECT. Hyperperfusion was seen suspiciously in the left medial occipital area. The interictal SPECT showed hypoperfusion in the left medial occipital area. Substracted ictal SPECT co-registered to MRI (SISCOM) demonstrated a hyperperfused area in the left posterior temporal area. Brain 18F-FDG PET demonstrated bilateral posterior temporo-occipital hypometabolism, but the left temporo-occipital hypometabolism were more prominent than the right one. Functional MRI showed left language dominance. Those results of the first presurgical evaluation demonstrated the focal epilepsy was originated from left occipital area. And the neocortical area is in the dominant hemisphere and has no structural abnormalities. Invasive presurgical evaluation, after placement of subdural electrodes over the left temporo-occipital areas, was planned for resective epilepsy surgery.


Mirror focus in a patient with intractable occipital lobe epilepsy.

Kim J, Shin HK, Hwang KJ, Choi SJ, Joo EY, Hong SB, Hong SC, Seo DW - J Epilepsy Res (2014)

Electrophysiologic results in the first presurgical evaluation. (A) Interictal epielptiform discharges are observed in left occipital area (vertical scale: 50 uv, horizontal scale: 1 sec). (B) Ictal EEG shows evolving rhythmic discharges with sharp waves in the left occipital region, spreading to the right occipital area. This ictal EEG indicates left occipital ictal onset zone (vertical scale: 100 uv, horizontal scale: 1 sec). The patient’s seizure was left versive seizure during this ictal recording.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4066626&req=5

f1-er-4-1-34-9: Electrophysiologic results in the first presurgical evaluation. (A) Interictal epielptiform discharges are observed in left occipital area (vertical scale: 50 uv, horizontal scale: 1 sec). (B) Ictal EEG shows evolving rhythmic discharges with sharp waves in the left occipital region, spreading to the right occipital area. This ictal EEG indicates left occipital ictal onset zone (vertical scale: 100 uv, horizontal scale: 1 sec). The patient’s seizure was left versive seizure during this ictal recording.
Mentions: A 10-year-old girl had epileptic seizures for 4 years. She was right handed and her epileptic seizures consisted of a visual aura with flashes, unresponsiveness and oro-ailimentary automatisms like lip smacking. The visual aura occurred in the left, right, or whole visual fields. Sometimes her seizures evolved into secondarily generalized seizures. Her seizures were not completely controlled by a polytherapy with carbamazepine, lamotrigine, and valproic acid. In a neurological examination, no lateralizing or focal neurological deficits were noted. She had no family history of epileptic seizure. Initially she was admitted to a long-term video EEG monitoring unit (EMU) for presurgical evaluation. During 9 day stay, interictal epileptileptifom discharges were seen frequently in the left occipital area (Fig. IA). Ictal events were 31 simple partial seizures (SPS) and 11 complex partial seizures (CPS). Among the 31 SPS, 12 visual auras occurred on her right side, whose ictal EEG showed left occipital discharges in 9 SPS and the remaining 3 auras showed no EEG changes. The other 19 visual auras occurred on her left side, whose ictal EEG revealed left occipital discharges in 2 SPS and the remaining 17 auras showed no EEG changes. Among the 11 CPS, right versive seizures are in 7 seizures, dialeptic seizures in 3 seizures, and left versive seizure in 1 seizure. Secondarily generalization occurred in 5 seizures. All ictal EEG changes started in the left occipital area (Fig. IB). Her 3.0T high resolution brain MRI showed no definite abnormalities. She underwent ictal and interictal Tc-99m ECD SPECT. Hyperperfusion was seen suspiciously in the left medial occipital area. The interictal SPECT showed hypoperfusion in the left medial occipital area. Substracted ictal SPECT co-registered to MRI (SISCOM) demonstrated a hyperperfused area in the left posterior temporal area. Brain 18F-FDG PET demonstrated bilateral posterior temporo-occipital hypometabolism, but the left temporo-occipital hypometabolism were more prominent than the right one. Functional MRI showed left language dominance. Those results of the first presurgical evaluation demonstrated the focal epilepsy was originated from left occipital area. And the neocortical area is in the dominant hemisphere and has no structural abnormalities. Invasive presurgical evaluation, after placement of subdural electrodes over the left temporo-occipital areas, was planned for resective epilepsy surgery.

Bottom Line: Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then.The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area.This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Busan;

ABSTRACT
Mirror focus is one of the evidence of progression in epilepsy, and also has practical points for curative resective epilepsy surgery. The mirror foci are related to the kindling phenomena that occur through interhemispheric callosal or commissural connections. A mirror focus means the secondary epileptogenic foci develop in the contralateral hemispheric homotopic area. Thus mirror foci are mostly reported in patients with temporal or frontal lobe epilepsy, but not in occipital lobe epilepsy. We have observed occipital lobe epilepsy with mirror focus. Before epilepsy surgery, the subject's seizure onset zone was observed in the left occipital area by ictal studies. Her seizures abated for 10 months after the resection of left occipital epileptogenic focus, but recurred then. The recurred seizures were originated from the right occipital area which was in the homotopic contralateral area. This case can be an evidence that occipital lobe epilepsy may have mirror foci, even though each occipital lobe has any direct interhemispheric callosal connections between them.

No MeSH data available.


Related in: MedlinePlus